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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License, Version 1.0 only
      6  * (the "License").  You may not use this file except in compliance
      7  * with the License.
      8  *
      9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
     10  * or http://www.opensolaris.org/os/licensing.
     11  * See the License for the specific language governing permissions
     12  * and limitations under the License.
     13  *
     14  * When distributing Covered Code, include this CDDL HEADER in each
     15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     16  * If applicable, add the following below this CDDL HEADER, with the
     17  * fields enclosed by brackets "[]" replaced with your own identifying
     18  * information: Portions Copyright [yyyy] [name of copyright owner]
     19  *
     20  * CDDL HEADER END
     21  */
     22 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     23 
     24 /*
     25  * get_myaddress.c
     26  *
     27  * Get client's IP address via ioctl.  This avoids using the NIS.
     28  * Copyright (C) 1990, Sun Microsystems, Inc.
     29  */
     30 
     31 #include <rpc/types.h>
     32 #include <rpc/pmap_prot.h>
     33 #include <sys/socket.h>
     34 #include <sys/sockio.h>
     35 #include <stdio.h>
     36 #include <net/if.h>
     37 #include <sys/ioctl.h>
     38 #include <arpa/inet.h>
     39 #include <netinet/in.h>
     40 #include <syslog.h>
     41 #include <malloc.h>
     42 #include <unistd.h>
     43 #include <stropts.h>
     44 #include <stdlib.h>
     45 #include <errno.h>
     46 
     47 /*
     48  * don't use gethostbyname, which would invoke NIS
     49  */
     50 void
     51 get_myaddress(struct sockaddr_in *addr)
     52 {
     53 	int s;
     54 	struct ifconf ifc;
     55 	struct ifreq ifreq, *ifr;
     56 	int len, numifs;
     57 	int ret;
     58 
     59 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
     60 	    syslog(LOG_ERR, "get_myaddress: socket: %m");
     61 	    exit(1);
     62 	}
     63 
     64 	do {
     65 		ret = ioctl(s, SIOCGIFNUM, (char *)&numifs);
     66 	} while (ret < 0 && (errno == EINTR || errno == EAGAIN));
     67 	if (ret < 0) {
     68 		syslog(LOG_ERR, "get_myaddress: ioctl: %m");
     69 		exit(1);
     70 	}
     71 
     72 	ifc.ifc_len = numifs * sizeof (struct ifreq);
     73 	if ((ifc.ifc_buf = (caddr_t)malloc(ifc.ifc_len)) == NULL) {
     74 		syslog(LOG_ERR, "get_myaddress: malloc: %m");
     75 		exit(1);
     76 	}
     77 
     78 	do {
     79 		ret = ioctl(s, SIOCGIFCONF, (char *)&ifc);
     80 	} while (ret < 0 && (errno == EINTR || errno == EAGAIN));
     81 	if (ret < 0) {
     82 		syslog(LOG_ERR,
     83 		    "get_myaddress: ioctl (get interface configuration): %m");
     84 		exit(1);
     85 	}
     86 
     87 	/*
     88 	 * set default to loopback in case nothing is found.
     89 	 */
     90 	addr->sin_family = AF_INET;
     91 	addr->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
     92 	addr->sin_port = htons(PMAPPORT);
     93 
     94 	ifr = ifc.ifc_req;
     95 	for (len = ifc.ifc_len; len > 0; len -= sizeof (ifreq), ifr++) {
     96 		ifreq = *ifr;
     97 		do {
     98 			ret = ioctl(s, SIOCGIFFLAGS, (char *)&ifreq);
     99 		} while (ret < 0 && (errno == EINTR || errno == EAGAIN));
    100 		if (ret < 0) {
    101 			syslog(LOG_ERR, "get_myaddress: ioctl: %m");
    102 			exit(1);
    103 		}
    104 		if (ifr->ifr_addr.sa_family != AF_INET)
    105 			continue;
    106 		if ((ifreq.ifr_flags & IFF_UP) == 0)
    107 			continue;
    108 		if (ifreq.ifr_flags & IFF_LOOPBACK)
    109 			continue;
    110 		if ((ifreq.ifr_flags & (IFF_MULTICAST | IFF_BROADCAST)) == 0)
    111 			continue;
    112 		*addr = *((struct sockaddr_in *)&ifr->ifr_addr);
    113 		addr->sin_port = htons(PMAPPORT);
    114 		break;
    115 	}
    116 	free(ifc.ifc_buf);
    117 	(void) close(s);
    118 }
    119